Local IL-4 expression in the lung reduces pulmonary influenza-virus-specific secondary cytotoxic T cell responses

We studied the effect of lung-specific IL-4 expression on the T cell response during primary and secondary heterologous infection with influenza virus by using transgenic mice that express IL-4 under a lung-specific promoter. Subsequent to primary infection with a type A/H1N1 influenza virus these transgenic mice exhibited similar local recruitment of CD4(+) and CD8(+) T cells and only slightly decreased virus-specific CTL activity. However, during secondary challenge with a heterologous influenza virus, the local infiltration with virus-specific, MHC class I-restricted CD8(+) T cells was significantly decreased compared to that of nontransgenic littermates. The ability of IL-4 transgenic mice to clear the heterologous infection was delayed but not abrogated. This was associated with a faster virus-neutralizing antibody response in IL-4 transgenic mice and with their ability to mount significant Th1 responses even in the presence of increased local IL-4 expression. Our observations demonstrate a negative regulatory effect of IL-4 on memory Tc1/CD8(+) T cells, but are also consistent with complementary mechanisms important for virus clearance such as virus-neutralizing antibodies. The reduction of memory CTL in the presence of IL-4 might have consequences for understanding the course of influenza infection in situations where T(H)2 immunity is increased.

Th cell-deficient mice control influenza virus infection more effectively than Th- and B cell-deficient mice: evidence for a Th-independent contribution by B cells to virus clearance

The notion that MHC class I- restricted CD8+ T (Tc) cells are capable of resolving autonomously infections with influenza virus is based largely on studies testing virus strains of low pathogenicity in CD4+ T (Th) cell-deficient/depleted mice. To test whether this holds also for pathogenic strains and to exclude possible contributions by B cells, we analyzed PR8 infection in Th cell-depleted B cell-deficient (muMT) mice. These mice, termed muMT (-CD4), showed 80% mortality after infection with a small dose of PR8, which resulted in insignificant mortality in intact or Th cell-depleted BALB/c mice. Infection of muMT(-CD4) mice with a virus of low pathogenicity was resolved without mortality, but, compared with intact BALB/c mice, with delay of approximately 5 and approximately 20 days from lung and nose, respectively. The low mortality of Th cell-depleted BALB/c mice suggested that B cells contributed to recovery in a Th-independent manner. This was verified by showing that transfer of 8-10 million T cell-depleted naive spleen cells into muMT(-CD4) mice 1 day before infection reduced mortality to 0%. The mechanism by which B cells improved recovery was investigated. We found no evidence that they operated by improving the lung-associated Tc response. Treatment of infected muMT(-CD4) mice with normal mouse serum spiked with hemagglutinin-specific IgM did not reduce mortality. Taken together, the data show that 1) the Tc response is capable of resolving autonomously (in conjunction with innate defenses) influenza virus infections, although with substantial delay compared with intact mice, and 2) B cells can contribute to recovery by a Th-independent mechanism.

Hemolytic uremic syndrome associated with influenza A virus infection in an adult renal allograft recipient: case report and review of the literature

Hemolytic uremic syndrome (HUS) is a rare but serious complication following renal transplantation. It usually develops early after transplantation, and ciclosporin treatment is the most common triggering factor. We report the case of a 35-year-old male with posttransplant HUS which developed 1 year after renal transplantation. He became febrile 4 days before the onset of HUS, and the significant rise in viral titer confirmed the diagnosis of influenza A virus infection. The association of ciclosporin treatment with HUS was unlikely, because of the late onset of HUS and the low ciclosporin trough levels. The patient was treated successfully without a dose reduction of ciclosporin. An etiologic relationship between influenza A virus and HUS was highly probable in our patient. We also review a total of 156 adult cases with HUS after renal transplantation described in the literature. The prognosis of posttransplant HUS differs according to the cause. The advent of ciclosporin has improved the graft survival rate and mortality of patients with rejection-induced HUS.

Mink lung cells and mixed mink lung and A549 cells for rapid detection of influenza virus and other respiratory viruses

Mink lung cells were more sensitive than the commonly used MDCK or pRhMK cells for rapid detection of influenza virus A from clinical specimens. Mixed Mv1Lu and A549 cells in a single shell vial were synergistic for detection of influenza virus A and were as sensitive as individual cells for detection of other respiratory viruses.

Effect of Hochu-ekki-to (TJ-41), a Japanese herbal medicine, on the survival of mice infected with influenza virus

The antiviral effect of Hochu-ekki-to (TJ-41), a Japanese herbal medicine, was investigated using mice infected with influenza virus. TJ-41 was found to increase the survival rate, prolong the mean survival days, suppress viral growth in bronchoalveolar labage fluid (BALF) and inhibit the lung index (lung consolidation) on day 4 after infection in mice infected with influenza, after the agent had been administered orally once daily from day 7 to 2 before infection and from day 0 to 4 after infection. Administration of TJ-41 decreased the BALF concentrations of IL-1alpha, IL-6 and GM-CSF, but not TNF-alpha or interferon-gamma (IFN-gamma), on day 4 after infection. In addition, TJ-41 elevated the level of IFN-alpha in BALF on day 2 after infection. Yet, TJ-41 did not show any inhibitory effect on the growth of influenza virus in vitro. These results suggest that TJ-41 exerts its inhibitory effect on influenza virus infection via enhancement of the host immune responses in this experimental murine system.

Absence of vertical transmission of infectious salmon anemia virus (ISAV) from individually infected Atlantic salmon Salmo salar

Atlantic salmon Salmo salar L. eggs were collected from grilse that were individually identified as ISAV-positive based on the detection of pathogen in ovarian fluid by RT-PCR. The eggs were fertilised, disinfected and reared under quarantine conditions. To address the possibility of vertical transmission, fertilised eggs, alevins and parr were screened for the virus by SHK-1 cell culture and RT-PCR. In addition, ISAV-negative parr were injected with homogenates of potentially infected eyed eggs. ISAV was not detected in eyed eggs, alevins or parr. No mortalities occurred among fish injected with the egg homogenates. These observations suggest the absence of a vertical transmission route for ISAV infection.

Naive, effector, and memory CD8 T cells in protection against pulmonary influenza virus infection: homing properties rather than initial frequencies are crucial

The goal of adoptive immunotherapy is to target a high number of persisting effector cells to the site of a virus infection or tumor. In this study, we compared the protective value of hemagglutinin peptide-specific CD8 T cells generated from the clone-4 TCR-transgenic mice, defined by different stages of their differentiation, against lethal pulmonary influenza infection. We show that the adoptive transfer of high numbers of Ag-specific unprimed, naive CD8 T cells failed to clear the pulmonary virus titer and to promote host survival. The same numbers of in vitro generated primary Ag-specific Tc1 effector cells, producing high amounts of IFN-gamma, or resting Tc1 memory cells, generated from these effectors, were protective. Highly activated CD62Llow Tc1 effectors accumulated in the lung with rapid kinetics and most efficiently reduced the pulmonary viral titer early during infection. The resting CD62Lhigh naive and memory populations first increased in cell numbers in the draining lymph nodes. Subsequently, memory cells accumulated more rapidly and to a greater extent in the lung lavage as compared with naive cells. Thus, effector cells are most effective against a localized virus infection, which correlates with their ability to rapidly distribute at the infected tissue site. The finding that similar numbers of naive Ag-specific CD8 T cells are not protective supports the view that qualitative differences between the two resting populations, the naive and the memory population, may play a major role in their protective value against disease.

Chemoprophylaxis of influenza A virus infections, with single doses of zanamivir, demonstrates that zanamivir is cleared slowly from the respiratory tract

Zanamivir (4-guanidino-2,4-dideoxy-2,3-dehydro-N-acetylneuraminic acid; Relenza; GG167) is a potent and highly specific neuraminidase (sialidase) inhibitor with inhibitory activity in vivo against both influenza A and B viruses. This compound has been extensively tested in both mouse and ferret models of influenza and has recently been approved for the treatment of influenza in Europe and Australasia. The compound markedly reduces the clinical course of disease in humans when given therapeutically by inhalation directly into the respiratory tract. In addition, experimental influenza infections in phase I clinical trials have shown the benefit of giving a single prophylactic dose of zanamivir in addition to a therapeutic regime. The studies reported here were designed to determine the persistence of zanamivir, as assessed by its antiviral activity in vivo, in the respiratory tracts of infected animals. We have shown that the prophylactic administration of zanamivir, when the drug is given in a single dose by the intranasal route, can significantly reduce lung virus titers in the mouse and can reduce both viral titers and symptoms in the ferret. Whole-body autoradiographical analyses of mice have indicated a long retention time for this compound in respiratory tract tissues when it is given in a single dose by the intranasal route. These results indicate that zanamivir may have clinical value as a prophylactic agent in protecting at-risk groups from influenza virus infection. In addition, these data may be useful in the design of prophylactic protocols for humans, in that the dosing schedule may only need to be intermittent to provide protection.

TH cells primed during influenza virus infection provide help for qualitatively distinct antibody responses to subsequent immunization

The quality of the primary Ab-forming cell (AFC) response in cervical lymph nodes and mediastinal lymph nodes of mice to intranasal influenza virus was strongly influenced by viral replicative capacity. IgA secretors were prominent in the early AFC response to infectious virus in mediastinal lymph nodes, while IgG expression was more frequent among isotypically switched AFC in cervical lymph nodes of the same mice; this pattern was reversed in the response to inactivated virus. Influenza viruses A/Puerto Rico/8/34 (A/PR8) and A/X-31 share six of eight genome segments, differing only in hemagglutinin (H1 in A/PR8, H3 in A/X-31) and neuraminidase (N1 in A/PR8, N2 in A/X-31) genes. These viruses therefore elicit extensively cross-reactive TH populations, though their glycoproteins are serologically unrelated. Mice recovered from an A/X-31 infection thus mount a primary B cell response against A/PR8 glycoproteins, when challenged with the latter virus, though this response can call upon memory TH cells. To assess the impact of memory TH populations on a primary Ab response, we compared the AFC response to inactivated A/PR8 in naive mice and mice that had cleared an A/X-31 infection. A/X-31 immune mice mounted a more vigorous AFC response against A/PR8 H1 and N1 glycoproteins than naive animals, when immunized intranasally with inactivated A/PR8. However the distribution of isotypes among H1/N1-specific AFC in lymph nodes of A/X-31-primed mice resembled that of naive mice. Evidently, in this functional context, memory TH cells retained the ability to help Ab responses different in quality from that generated during their primary reaction.

Mice lacking the transcription factor subunit Rel can clear an influenza infection and have functional anti-viral cytotoxic T cells but do not develop an optimal antibody response

Rel, a haemopoietic cell-restricted member of the NF-kappaB/Rel family of transcription factors, has recently been shown to be important in the function of B and T lymphocytes. In an attempt to understand the role of this protein in the immune response, we examined the ability of Rel(-/-) mice to counter an influenza virus infection. Normal levels of virus-specific cytotoxic T cells induced in Rel(-/-) mice were able to clear virus from the lungs, albeit with somewhat delayed kinetics compared to normal mice. Rel(-/-) mice did, however, display a markedly reduced T cell proliferative response to the virus, and exhibited impaired local and systemic influenza virus-specific antibody responses. This defect was sufficient to result in an inability of vaccinated mice, but not of previously infected mice, to acquire antibody-dependent protective immunity to reinfection with the same virus. These findings establish that during the response to influenza virus, Rel function allows optimal development of humoral immunity, a role that apparently cannot be fulfilled by other NF-kappaB/Rel proteins.

Differential production of proinflammatory cytokines in the pig lung during different respiratory virus infections: correlations with pathogenicity

The acute stages of infection with swine influenza virus (SIV), porcine respiratory coronavirus (PRCV) and porcine reproductive-respiratory syndrome virus (PRRSV) were shown to differ in terms of clinical and lung inflammatory effects and proinflammatory cytokine profiles in bronchoalveolar lavage (BAL) fluids. Caesarian-derived colostrum-deprived pigs were inoculated intratracheally with one of the three viruses. SIV infection was followed within 1 day post inoculation (d PI) by characteristic respiratory and general signs, and excessive lung epithelial desquamation and neutrophil infiltration (38 to 56 per cent of BAL cells at 1 d PI vs 0 to 1 per cent in controls). High concentrations of bioactive interferon-alpha (IFN -alpha), tumour necrosis factor-alpha (TNF -alpha) and interleukin-1 (IL -1) coincided with peak symptoms and neutrophil infiltration. PRCV infection was asymptomatic and produced a mild bronchointerstitial pneumonitis and neutrophil infiltration (13 to 22 per cent of BAL cells at 4 d PI). IFN -alpha titres parallelled those found during SIV infection, TNF -alpha was negligible and IL -1 undetectable. PRRSV infection induced anorexia and lethargy between 3 and 5 d PI. There was marked infiltration with mononuclear cells in alveolar septa and BAL fluids between 7 and 10 d PI, while neutrophils remained at less than 11 per cent of BAL cells at any time. IL -1 was produced from three throughout 10 d PI, while IFN -alpha production was minimal and TNF -alpha undetectable. These data strongly suggest that proinflammatory cytokines can be important mediators of viral respiratory disease.

Detection of influenza virus RNA by reverse transcription-PCR and proinflammatory cytokines in influenza-virus-associated encephalopathy

Eleven children with acute encephalopathy associated with an influenza virus infection were treated during the 1997-1998 influenza season. Reverse transcription-polymerase chain reaction (RT-PCR) assay was used to detect the viral genome in peripheral blood and cerebrospinal fluid (CSF) samples. The results were compared with those of control influenza patients without neurological complications. Viral RNA was detected only in the peripheral blood mononuclear cells of one patient with influenza-virus-associated encephalopathy (1 of 9; 11%) and in the CSF of another patient (1 of 11;9%). RT-PCR was negative in the blood of all the controls, but the percentage of RT-PCR-positive samples in the two groups was not significantly different. Cytokines and soluble cytokine receptors in plasma and CSF were then quantified using an enzyme-linked immunosorbent assay. The CSF concentrations of soluble tumor necrosis factor receptor-1 were elevated in two patients and interleukin-6 (IL-6) was elevated in one patient with influenza-virus-associated encephalopathy. On the other hand, the plasma concentrations of IL-6 were elevated in four of nine patients. The number of encephalopathy patients who had elevated plasma concentrations of IL-6 100 pg/ml was significantly higher than that of controls (P= .01). In conclusion, the infrequent detection of the viral genome in the CSF and blood showed that direct invasion of the virus into the central nervous system was an uncommon event. Proinflammatory cytokines and soluble cytokine receptors may mediate the disease. The high plasma concentration of IL-6 could be an indicator of the progression to encephalopathy.

The role of endothelin in mediating virus-induced changes in endothelinB receptor density in mouse airways

Emerging evidence supports a mediator role for endothelin (ET)-1 in airway diseases including asthma. Respiratory tract viral infections, are associated with increased levels of ET and altered ET receptor density and function in murine airways. To determine whether these virus-induced effects are causally linked, perhaps involving ET-1-induced ET(B) receptor downregulation, the current study investigated the influence of in vivo administration of CGS 26303, an ET-converting enzyme inhibitor, on virus-induced changes in ET-content and ET(B) receptor density. CGS 26303 (5 mg x kg(-1) x day(-1)) or placebo was administered to mice via osmotic minipumps implanted subcutaneously. Two days after implantation, mice were inoculated with influenza A/PR-8/34 virus or sham-infected, and all measurements were performed on tissue obtained on the fourth day post-inoculation. Viral infection was associated with elevated levels of immunoreactive ET and decreased densities of ET(B) receptors in murine airways. Both of these effects were attenuated in virus-infected mice that had received CGS 26303. Virus-induced increases in wet lung weight were also inhibited by CGS 26303. Importantly, administration of CGS 26303 had no effect on the titres of infectious virus in the lungs and similarly, viral infection had no effect on the plasma levels of free CGS 26303. In summary, CGS 26303 inhibited the virus-induced changes in both immunoreactive endothelin content and endothelinB receptor density. These findings are consistent with the postulate that the elevated epithelial expression of endothelin-1 during respiratory tract viral infection is a contributing factor in the downregulation of endothelinB receptors in airway smooth muscle. Whether inhibitors of endothelin synthesis attenuate virus-induced exacerbations of asthma or airways hyperresponsiveness remains to be established.

Antisense oligonucleotides directed against the viral RNA polymerase gene enhance survival of mice infected with influenza A

We have investigated the ability of antisense phosphorothioate oligonucleotides to enhance the survival of mice infected with influenza A virus. The oligonucleotides were complementary to sequences surrounding the translation initiation codons of the viral PB2 or PA genes (PB2-as or PA-as, respectively) of the influenza A virus RNA polymerases. Intravenous administration of PB2-as in a complex with a cationic liposome, Tfx-10, significantly prolonged the mean survival time in days and increased overall survival rates of mice infected with the influenza A virus. Liposomally encapsulated PB2-as inhibited viral growth in lung tissues and reduced pulmonary consolidations. Liposomally encapsulated PB2-as could be an effective therapeutic agent against influenza A virus.

Time course tissue distribution of infectious salmon anaemia virus in experimentally infected Atlantic salmon Salmo salar

Atlantic salmon Salmo salar L. were injected intraperitoneally with infectious salmon anaemia virus (ISAV)-infective tissue homogenate to clarify the tissue distribution of ISAV in a time course study. Fish were sampled at 11 different intervals between 1 and 40 d post-infection (p.i.) and mid-kidney, head kidney, liver, spleen, intestine, gills, muscle and heart were tested for the presence of ISAV by reverse transcriptase polymerase chain reaction (RT-PCR). The results showed that during a disease outbreak, ISAV is present in most organs. It was possible to detect ISAV at all sampling times in at least 1 of the fish examined. However, for the first 8 d p.i. positive RT-PCR results were predominantly found in samples from the head kidney and mid-kidney. Fish giving positive samples after Day 13 p.i. were RT-PCR positive in most organs. These results indicated that between Days 8 to 13 p.i. considerable replication of the virus occurred, combined with wide tissue dissemination.

Modified M2 proteins produce heterotypic immunity against influenza A virus

Vaccination with the influenza A transmembrane protein M2 provides enhanced viral clearance and recovery from influenza A virus infection in mice. However, the high degree of hydrophobicity of the protein limits its purification for vaccine purposes. We have attempted to alter the structure of the M2 protein to allow high level recombinant expression in Escherichia coli, to reduce its hydrophobicity and improve protein solubility, thus improving its properties as a vaccine subunit candidate. Constructs investigated include deletion of the transmembrane domain of M2 (residues 26-43) and an extended deletion (residues 26-55). A full-length M2 protein was not pursued because of poor expression, even in the presence of amantadine. Expressed as glutathione S-transferase fusion proteins and used to vaccinate mice, either deletion construct was found to raise M2-specific serum antibodies and enhance viral clearance in mice challenged with homologous and heterologous influenza A viruses. Enzymatic cleavage from the GST fusion domain produces soluble protein giving similar results. The results demonstrate that large alterations of M2 protein structure can improve its isolation and purification characteristics without detracting from its immunogenic properties.

Immunization with influenza A virus hemagglutinin and neuraminidase produced in recombinant baculovirus results in a balanced and broadened immune response superior to conventional vaccine

Influenza A virus hemagglutinin (HA) and neuraminidase (NA) from A/Nanchang/933/95 were expressed by recombinant baculovirus-infected insect cell lines. HA and NA were chromatographically purified then combined in a single vaccine preparation. Immunization of mice with this preparation resulted in high titers of antibodies to both HA and NA equivalent for each antigen to titers in animals immunized with either antigen alone. Anti-NA antibody titers, measured by either enzyme linked immunoabsorbant assay or neuraminidase inhibition test were higher in the combined recombinant vaccine than in conventional monovalent inactivated vaccine. There was no difference in the anti-HA antibody titers between these two vaccine preparations. Homotypic and closely related heterotypic infections were suppressed and greater reduction in viral replication was observed following a distantly related heterotypic infectious challenge than was observed with conventional inactivated vaccine. The combined HA and NA vaccine takes advantage of the equivalent immunogenicity of dissociated HA and NA, to produce a broader and more balanced immune response to both antigens, without the HA-dominant antigenic competition that occurs with natural infection or immunization with conventional vaccine. Additionally, the recombinant baculovirus expression system offers a reliable rapid production system without the use of massive numbers of embryonated chicken eggs. These studies in a mouse model system suggest that production of a combined HA and NA vaccine from recombinant baculovirus offers an improved alternative to conventional inactivated influenza vaccine.

Epitope-specific cytotoxic T lymphocyte induction by minigene DNA immunization

Plasmid DNA vaccines encoding full-length antigen often induce both potent antibody and cytotoxic T lymphocyte (CTL) responses. Here, we examine strategies to exclusively elicit epitope-specific CTL responses using DNA constructs expressing a minimal class I MHC-restricted epitope of the nucleoprotein (NP) of influenza virus. The effects of the addition of an ER leader sequence or cytokine combination on minigene-induced CTL responses in vivo were assessed following both delivery by needle injection into skeletal muscle and by gene gun bombardment into skin epidermis. Our data indicate that the leader sequence enhanced the magnitude of the CTL responses, whereas co-injection of the cytokine genes IL-12 and GM-CSF had a minimal effect. An antibody response against NP was not observed in any of the mice receiving the minigene constructs.

Epizootic of equine influenza in 1969 in Poland

Epidemiological observations on the course and spread of equine influenza in Poland during the 1969 epizootic were carried out. The dynamics of the spread of the disease in the country are shown graphically by voivodship. The disease incidence and mortality rates for the entire country are also shown. The highest incidence of disease and mortality rates were found to be in November 1969. A/equi-2/Warsaw/69 was identified as the causal virus. It caused the largest epizootic in the country since 1954.

Spontaneous release of stable viral double-stranded RNA into the extracellular medium by influenza virus-infected MDCK epithelial cells: implications for the viral acute phase response

The viral factor responsible for triggering the acute phase response, or 'flu' syndrome, associated with many acute viral infections is not defined. One candidate viral factor is double-stranded RNA (dsRNA) generated during viral replication. In this report we demonstrate by reverse-transcriptase polymerase-chain reaction that nuclease-stable viral RNA was released from influenza-infected MDCK epithelial cells at the time of cell lysis. Removal of virion-associated RNA by ultracentrifugation left equal amounts of positive- and negative-strand viral RNA in the medium that resisted degradation by endogenous RNase in the medium and by exogenous RNase added prior to phenol extraction. These data are the first demonstration that viral RNA with characteristics of dsRNA is spontaneously released from dying influenza virus-infected cells, and thus is available to amplify cytokine induction and contribute to systemic disease.

Fish oil feeding delays influenza virus clearance and impairs production of interferon-gamma and virus-specific immunoglobulin A in the lungs of mice

Ingestion of fish oil can suppress the inflammatory response to injury and may impair host resistance to infection. To investigate the effect of a diet containing fish oil on immunity to viral infection, 148 BALB/c mice were fed diets containing 3 g/100 g of sunflower oil with either 17 g/100 g of fish oil or beef tallow for 14 d before intranasal challenge with live influenza virus. At d 1 and d 5 after infection, the mice fed fish oil had higher lung viral load and lower body weight (P < 0.05). In addition to the greater viral load and weight loss at d 5 after infection, the fish oil group consumed less food (P < 0.05) while the beef tallow group was clearing the virus, had regained their preinfection weights and was returning to their preinfection food consumption. The fish oil group had impaired production of lung interferon-gamma (IFN-gamma), serum immunoglobulin (Ig) G and lung IgA-specific antibodies (all P < 0. 05) although lung IFN-alpha/beta and the relative proportions of bronchial lymph node CD4+ and CD8+ T lymphocytes did not differ between groups after infection. The present study demonstrates a delay in virus clearance in mice fed fish oil associated with reduced IFN-gamma and antibody production and a greater weight loss and suppression of appetite following influenza virus infection. However, differences observed during the course of infection did not affect the ultimate outcome as both groups cleared the virus and returned to preinfection food consumption and body weight by d 7.

Isolation of infectious salmon anemia virus (ISAV) from Atlantic salmon in New Brunswick, Canada

Infectious salmon anemia virus (ISAV) was isolated at a marine grow-out site in New Brunswick, Canada, from Atlantic salmon Salmo salar which experienced mortalities due to hemorrhagic kidney syndrome (HKS). Of 20 fish sampled in this study, 14 showed histologically various degrees of interstitial hemorrhaging, tubular epithelial degeneration and necrosis, and tubular casts in the posterior kidney, typical of HKS. Posterior kidney and spleen homogenates produced a cytopathic effect on chinook salmon embryo (CHSE-214) cells 10 to 14 d after inoculation. Pleomorphic virus particles in the size range 80 to 120 nm were seen by electron microscopy. The virus was confirmed as ISAV using reverse transcriptase-polymerase chain reaction (RT-PCR). This is a systematic diagnostic study of the isolation of ISAV on the North American continent and the first description of the growth of ISAV on the CHSE-214 cell line.